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A Cisgenic Approach in the Transformation of Bread Wheat cv. Saratovskaya 29 with Class I Chitinase Gene
Abstract
Background:
Bread wheat is one of the major crops grown worldwide, showing high demand for new varieties with traits such as pathogen resistance. As the public acceptance of transgenic plants remains low, a novel approach – cisgenesis – is being developed to introduce the genes from the same or closely related species.
Objective:
This study presents a cisgenic approach used for the transformation of wheat with class I chitinase gene derived from T. aestivum cv. Stepnaya 15, co-transformed with acetohydroxyacid synthase gene that provides tolerance to imidazolinone herbicides.
Methods:
Calli from immature embryos of spring bread wheat Triticum aestivum cv. Saratovskaya 29 were used for co-transformation with two independent Minimal Expression Units (MEUs): class I chitinase and Acetohydroxyacid Synthase (AHAS) gene. For identification of cisgenic plants, genomic DNA was extracted from the leaves of imazethapyr-resistant regenerant plants at the plantlets stage and screened by polymerase chain reaction. The efficiency of transformation was calculated as the relation of regenerated plants with chitinase gene insert to the total number of calli in the experiment.
Results:
The average transformation efficiency in four series of experiments (total number of calli - 2299) was found to be 1.84% (ranging from 0.3% to 3.4%), while total co-transformation efficiency reached 87.93%.
Conclusion:
The high efficiency of co-transformation in the experiment promotes it as a very useful technique for the production of wheat lines, free of the selectable marker gene. To our knowledge, this is the first report of cisgenic bread wheat, where both target and selectable genes are derived from wheat.